Question

The jumping gait of the kangaroo is efficient because energy is
stored in the stretch of stout tendons in the legs; the kangaroo
literally bounces with each stride. We can model the bouncing of a
kangaroo as the bouncing of a mass on a spring. A 82kg kangaroo
hits the ground, the tendons stretch to a maximum length, and the
rebound causes the kangaroo to leave the ground approximately 0.15s
after its feet first touch.

Modeling this as the motion of a mass on a spring, what is the
period of the motion?
T=?